Jacob (‘Jack’) Pepys was an outstanding clinical researcher who made substantial contributions to our understanding of allergic diseases. He was born in Johannesburg and entered the Witwatersrand University Medical School at the age of 15, graduating six years later. He was not allowed to practice until his 21st birthday and took a temporary research post that started his lifelong interest in allergy. However, once registered, he worked as a general practitioner for twelve years.

In 1948 he moved to London where he subsequently set up the first British academic department devoted to allergic diseases at the Brompton Hospital. He approached his work with enormous enthusiasm, and his leadership skills and sense of humour combined to produce a centre of excellence. The major scientific advances of the Pepys team included identification of the cause of farmer’s lung and subsequently many other forms of allergic alveolitis, the clinical and immunological characterization of allergic bronchopulmonary aspergillosis, the introduction of bronchial provocation tests with allergens and the identification of numerous causes of occupational asthma. His overall contributions to occupational allergic disease were immense.

He was a great traveller and had friends and scientific colleagues in virtually every corner of the globe. The Brompton clinical immunology department attracted a huge international following of postdoctoral fellows.

A prolific and clear writer, Jack Pepys published over two hundred articles in national and international journals. He received many academic distinctions and awards and was president of the British Society for Allergy and Clinical Immunology as well as the International Association of Allergology and Clinical Immunology.

Jack Pepys was not only an outstanding original researcher, he also had fine qualities as a physician and teacher. With his wit and open personality he was always in demand as a speaker. He had an endless repertoire of clinical anecdotes and amusing stories and his observations on life in general and his colleagues in particular ranged from the poignant to the hilarious.

He had a hard struggle bringing his new and original concepts to the British medical establishment but eventually succeeded as a result of his hard work, single-minded and dedicated commitment to his subject, coupled with his personal blend of firmness and modesty.

A few months before his death a special international symposium was held to honour Jack and his achievements. There were many tributes. He was described variously as "a great and gentle man" and "the epitome of the British gentleman." Great emphasis was given to his international role and his ability to bridge fundamental and clinical research. He made a deep impression on his friends and colleagues with his astuteness and curiosity about mechanisms of disease.

He married Rhoda (née Kussel), a gifted artist, in 1938. Their daughter, Sandra, is also an artist and their son, Mark, is professor of immunological medicine at the Royal Postgraduate Medical School.

Jack developed a nasopharyngeal carcinoma for which he received several courses of radiotherapy and chemotherapy and he suffered many complications of treatment. He bore all this with stoicism and great bravery and remarkably continued to work literally until his death.